The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 65mm F2 DG DN and the Leica APO-SL 75mm F2 ASPH for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Leica APO-SL 75mm F2 ASPH is the longer of the two lenses at 102mm. The Sigma 65mm F2 DG DN with a length of 75mm, is 27mm shorter. Besides being longer, the Leica APO-SL 75mm F2 ASPH also has a larger diameter of 73mm compared to the Sigma 65mm F2 DG DN's 72mm diameter.
The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Sigma 65mm F2 DG DN weighs 405g, which means it is 315g (43%) lighter than the Leica APO-SL 75mm F2 ASPH which has a weight of 720g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Leica L Mount for size comparison purposes.
Standard Prime Lenses in Leica L Mount for Size Comparison
Lens Mounts
Both the Sigma 65mm F2 DG DN and the Leica APO-SL 75mm F2 ASPH has the same Leica L lens mount. Some of the latest released cameras that are compatible with the Leica L lenses are Panasonic S5 II, Panasonic S5 II X and Sigma fp L.
Sigma 65mm F2 DG DN is also available in Sony E mount.
Focal Range
Sigma 65mm F2 DG DN is a prime lens with fixed focal lenght of 65mm. Leica APO-SL 75mm F2 ASPH is a prime lens with fixed focal lenght of 75mm.